A Colles fracture is a fracture of the forearm radius bone close to the wrist joint. In treating such a fracture, the physician must manipulate the two halves of bone on either side of the fracture back together to form a stable volar buttress. Once the two bond halves are mated, they must be fixed together for a period long enough for the bones to mend.
Various devices are known in the prior art for external fixation of bone fractures. For example, U.S. patent application Ser. No. 085,996, filed on Oct. 18, 1979, discloses an external fixature device comprised of longitudinal, adjustable length frame members held in parallel by semicircular frame members which have a plurality of holes in them for receiving fixation pin clamps. Because hooks and not slots are used, the combination of relative angles of the pins one to the other and spacing of the pins from each other are not continuously variable and therefore there are less than an infinite number of combinations. U.S. Pat. No. 1,789,060 discloses a bond fracture clamp utilizes four pins which are drilled and tapped into the bone halves and which are themselves externally stabilized by a framework divided into two halves and connected in the center by a ball and socket joint. This joint may be manipulated to the proper position and locked in place.
Russian Pat. No. 560,605 shows a device using two pins wherein each pin is passed completely through one of the bone halves and out from the other side of the limb. The pins are attached to semicircular slotted frames by adjustable couplings such that their angle relative to each other can be changed. These semicircular couplings themselves are connected via rods which are connected to each end of the semicircle, and to an X-like frame structure which pivots at its intersection point.
U.S. Pat. No. 4,003,340 teaches a surgical compression instrument with an outer ring having longitudinal connecting members with a smaller ring inside connected to the larger ring by radial coupling members. The smaller ring has clamps for fixature needles which are passed completely through the bone fragment on either side of the fracture. The radial couplers are threaded so that the inner ring can move in any direction and turn within the outer ring. The inner ring can also be positioned in a plane turned at an angle with respect to the plane of the outer ring.
Russian Pat. No. 591,182 discloses a device for aligning the head with the hip such that spinal injuries may be treated. The device teaches a semicircular slotted frame at the top having pins which can be screwed into the scalp. The semicircular fixture is connected by vertical rods to a hip device which fits around the pelvic region of the patient and has pins which are surgically passed through the pelvic bone to stabilize it. The three vertical rods passing through the semicircular fixture about the head pass through slots and that fixture can be clamped such that the fixture, once clamped to the skull, can then be twisted to orient the head and spine in the proper direction and then clamped to prevent any further movement.
U.S. Pat. No. 3,727,610 teaches a fixation device for a diaphyses fracture. The device comprises two fixation pins which are clamped to semicircular frame devices having slots therein such that the angles of the pins relative to each other can be varied and permanently clamped. Two pins are attached to each of the semicircular frame devices and passed completely through the bone and limb. The two semicircular frame members are connected to each other by threaded rods and couplings such that their longitudinal distance from each other can be varied.
U.S. Pat. No. 3,997,397 discloses a device comprised of several circular rings having pins clamped to said rings which pass entirely through bone segments. The rings are connected to each other by springs such that once the pins are passed through the bone fragments, the springs will keep the fragments together by applying compression forces thereto.
The well-known Roger Anderson device is designed for reducing unstable Colles fractures. The Roger Anderson device consists of two unthreaded rods which are placed on the forearm over the fracture site. Four knuckle joints, which hold fixation pins, are slidably connected to the rods so that they may be inserted into the radius bone on the elbow side of the fracture and into the second and third metacarpal bones on the hand side of the fracture. After the fracture is reduced, the physician inserts the pins and slides the knuckle joints to the proper position and clamps them down. The upper portions of the pins are coupled via crossed members and knuckle joints such that the angle of the pins with respect to each other can be changed and clamped. The disadvantage of this device is that eight knuckle joint type clamps are involved in the process of clamping the fracture. Two persons may be required in setting the fracture, i.e., one person holding the bones in correct orientation while the other person manipulates the pins, knuckle joints, and connecting rods and clamp screws. The complexity and physical dexterity required renders this device difficult to use. In addition, the stability of the device leaves something to be desired if any one of the clamps becomes loose. If any clamp device loosens, the entire parallel piped structure may be weakened thereby altering the compressive forces applied to the fracture location. Also, the compressive forces in the fracture area are obtained by manually pressing the bone halves together to the desired compressive level, then sliding the knuckle joints holding the pins inserted into the bones to positions required to maintain the compressive force. Then all knuckle joints must be tightened to maintain compression.